1. Put the flour, eggs, salt, oil, vinegar and water into a mixing bowl. Knead the dough and let it rest for 15 minutes.
2. Divide the dough into 12 parts. Let stand 15 minutes.
3. Stretch the dough with a rolling pin. Place the layers of dough in a greased pan.
4. Top each layer with melted butter. When you have laid out half of the layers, sprinkle with walnuts. Continue layering all the way to the end, then cut the cake into cubes. Bake at 360F/180C for 60 minutes.
5. Prepare a syrup of sugar, water and lemon juice. Pour over the cake, then serve